The present invention relates to a plate used for transferring DNA sequencing samples to a separation/detection system. The plate of the present invention is capable of transferring at one and the same time a plurality of reaction products produced in wells of a multi-reaction plate to an analyzer using a large number of capillaries, such as an electrophoretic analyzer.
The present invention further relates to a method for transferring DNA sequencing samples utilizing the plate mentioned above, a method for purifying DNA sequencing samples utilizing said plate, and a method for purifying and transferring DNA sequencing samples utilizing said plate.
With recent developments of DNA detection methods utilizing laser fluorescence, laser fluorescence DNA sequencers have become widely used. Developments of such techniques have also enabled analysis of a large number of samples in, for example, genome researches and DNA diagnoses (approximately 100 lanes or less/2 operations/day/apparatus). Typical examples of such laser sequencers are those utilizing slab-type gels and capillary-type gels.
In order to analyze a larger number of samples than is possible by current techniques, equipment having a larger number of electrophoresis lanes (for example, 200 to 1000 lanes/operation) are required. Such equipment (including, for example multi-capillary sequencers) are under development.
However, as the number of lanes increases, the operation of transferring samples to the lanes becomes more time-consuming and more burdensome. That is, when a large number of samples are loaded on each of capillary gels, each sample should be injected into each capillary by contacting one end of the capillaries with a fine electrode lead. Therefore, development of a technique enabling quick and easy transfer of a large number of samples is urgently needed.
Further, introducing reaction solutions into the wells of micro-titer plates also requires more time as the number of the wells increases. Therefore, a means for rapidly introducing reaction solutions into the wells is also urgently desired.
Furthermore, following DNA sequencing reactions fragments of various lengths labeled with fluorescent labels are usually present with unreacted labeling reagent. The major part of such coexisting unreacted labeling reagent is usually not utilized in the reaction and exists in the reaction mixture in free form. If such a reaction solution is used for electrophoresis as it is, the high concentration of fluorescent label will migrate with the sample and can generate a signal markedly stronger than those produced by the target sequences. As a result, the desired analysis becomes impossible to perform. Accordingly, the fluorescent label should be removed before electrophoretic separation. However, removal of the unreacted labeling reagent in hundreds of samples requires much labor and time. As a result, even if efficiency of DNA sequencing methods itself is improved, the rate-determining factor would occur before sequencing.